1309231 (1) 玖、發明說明 【發明所屬之技術領域】1309231 (1) Description of the invention [Technical field to which the invention pertains]
本發明係關於一種改良的用於製造玻璃物件之方法， 包括：一透過所謂溶膠·凝膠技術製備標的材料的凝膠之 步驟，一經由在惰性流體的存在中，於凝膠細孔內所含溶 劑之臨界壓力與溫度下，加壓加熱以乾燥所得凝膠之步驟 ’及一最後熱處理之步驟，以得到該玻璃物件。當然，於 因爲其他應用，要抽取某些攸關的中間產物，例如溶膠本 身，或合成前之凝膠，之情況中，該方法可於任一步驟停 止。 【先前技術】The present invention relates to an improved method for producing a glass article, comprising: a step of preparing a gel of a target material by a so-called sol-gel technique, in the presence of an inert fluid, in a pore of the gel The step of treating the resulting gel with a critical pressure and temperature at a critical pressure and temperature, and a final heat treatment step, to obtain the glass article. Of course, because of other applications, it is necessary to extract certain intermediates, such as the sol itself, or the gel before synthesis, in which case the method can be stopped at any step. [Prior Art]
已知者“溶膠-凝膠”一詞係關於且涵蓋製造乾凝膠之 廣泛程序領域，其於該情況中，可經壓密以製備對應的玻 璃體。乾凝膠本體可用爲催化劑載體，或用在隔熱領域中 ，而由是所得玻璃可應用於多種技術領域中，主要是用在 光學與半導體領域中。 通常，玻璃是藉由熔化適當粉末之混合物’隨後使已 熔化之產品凝固。相反地，溶膠-凝膠法係使用標的材料 的先質之溶液並避免通過熔化步驟，經常會失控。 技藝中已知的所有溶膠·凝膠法包括下列諸步驟： -製備形成作爲最終玻璃物件之目標的氧化物之元素 (Μ )的化合物所形成之先質的溶液或懸浮液， -依據下面的反應用酸或鹼催化，將該先質水解形成 -5- (2) 1309231 m-oh 基The term "sol-gel" is used in the context of and encompasses a wide range of procedures for making xerogels, in which case it can be compacted to produce a corresponding glass body. The xerogel body can be used as a catalyst carrier or in the field of thermal insulation, and the resulting glass can be used in various fields of technology, mainly in the fields of optics and semiconductors. Typically, the glass is formed by melting a mixture of suitable powders followed by solidification of the molten product. Conversely, the sol-gel process uses a solution of the precursor of the target material and avoids passing through the melting step, often out of control. All sol-gel processes known in the art include the following steps: - preparing a precursor solution or suspension formed by a compound which forms an element of the oxide (Μ) which is the target of the final glass article, - according to the following The reaction is catalyzed by an acid or a base to hydrolyze the precursor to form a 5-(2) 1309231 m-oh group.
MXn + nH20 M(OH)n + nHX 其中未知大寫字母具有後文所述意義。所得之混合 物亦即溶液或膠體懸浮液稱爲凝膠， -依據下面的反應將M-OH基聚縮合 M-OH + M-OH Μ-0-Μ + H20 其特徵在於液體黏度之增加（凝膠化）與稱爲凝膠 之基質的同時形成， -將凝膠乾燥形成一多孔整體型物體；該乾燥可藉由 控制溶劑蒸發來進行，其產生所謂的乾凝膠（ xerogel ) ’或經由溶劑超臨界萃取，其所謂的氣 凝膠（aerogel):如上所述，乾燥凝膠即可以其 本身供工業所用，或其可藉由熱處理密實化以製 備玻璃體。 溶膠-凝膠技術’在用於生產玻璃時，因所有程序參 數有較佳的控制且因而，最終產品有較高純度的特徵，故 而在熔化技術上有其優點。 製造玻璃體，主要是以矽氧化物爲基底，所用的溶 膠-凝膠法在許多專利中有揭示。例如，美國專利第 4,3 24,5 76號與第5,076,9 80號之方法係於其中先質爲烷氧 化物，特別是四甲氧基正矽烷（TMOS)及正矽酸四乙基酯 (TEOS)。目標是要最小化生產成本與改善最終產品之品質 之改良方法在美國專利第4,6 8 0,04 8號，第4,681,615號 及第5,207,814號或在歐洲專利第5 8 6，0 ] 3號中有揭示， (3) 1309231 其中也揭示於熱解或膠體形狀下添加矽石於 溶膠。依據此等專利內容，在製造光學組件 裝置之方法中，特別要注意的是，其凝膠步驟 與，特別是依據歐洲專利第5 8 6，0 1 3號，其凝 在高於凝膠內所含溶劑的臨界値之溫度與壓力 最終產品相當不錯，不過，高臨界乾燥技 以特定材料建立之裝置，且再者，其進行會耗 。美國專利第5,243,769號與第5,473,826號 孔型凝膠之方法，係經由溶膠-凝膠法製成， 力低於凝膠溶劑之臨界値，包括於浸入乾燥溶 於一壓力室內且增加其溫度之下的凝膠凝固。 是在以上述溶劑蒸氣飽和之惰性氣體中，而於 不用此等惰性氣體且不持續監視內部壓力。不 度與壓力相對於臨界値的偏差係低者，且所有 在壓力室中使用個別量的乾燥溶劑，此迫使隨 收程序。 本案申請人頃發現可以達到不具上述缺點 物件方法，此亦爲本發明之主要目標，該方 膠-凝膠技術製造凝膠，以及在低於溶劑臨界 壓力’同時對比等有很高偏差的情況之下乾燥 ’該方法也可製備及分離任何標的中間產物， 的溶膠，或熱密實化前的凝膠。此類中間產物 離轉而是本發明的附加目標，且彼等也完全屬 圍之內。 :氧化物所得 幾乎是最終 (聚縮合） 膠乾燥，是 下進行的。 術需要用到 費大量能量 揭示乾燥多 其溫度與壓 劑內之後， 於前者中， 後者中，則 過，溶劑溫 方法都包括 後要用到回 的製造玻璃 法包括用溶 値的溫度與 凝膠。當然 例如要水解 的製造與分 於本發明範 13092¾件 (4) 法 2A :第 93100697號專利申請案 r._______中文說明書替換頁民國94年8月29日修正 I ΐ :i yl·.. Ή ' -ϊ · ；-；·. . ,v ： i 94； 8/19 _____ ‘ 因此本發明的一項目標係一種用於製造玻璃物件之方 其包括下列操作： a )製備至少一種下面化學式的化合物之水溶液或水 醇溶液，或懸浮液，MXn + nH20 M(OH)n + nHX where unknown uppercase letters have the meanings described below. The resulting mixture, ie the solution or colloidal suspension, is referred to as a gel, - the M-OH group is polycondensed according to the following reaction M-OH + M-OH Μ-0-Μ + H20 which is characterized by an increase in the viscosity of the liquid (coagulation) Gelling) is formed simultaneously with a matrix called a gel, - drying the gel to form a porous monolithic object; the drying can be carried out by controlling the evaporation of the solvent, which produces a so-called xerogel (or xerogel) or By solvent supercritical extraction, a so-called aerogel: as described above, the dried gel can be used commercially by itself, or it can be densified by heat treatment to prepare a glass body. The sol-gel technique has advantages in melting technology when it is used for the production of glass because of the better control of all the program parameters and, therefore, the final product has a higher purity. The vitreous is produced, mainly based on cerium oxide, and the sol-gel method used is disclosed in many patents. For example, the methods of U.S. Patent Nos. 4, 3, 24, 5, 76 and 5, 076, 9 80 are in which the precursor is an alkoxide, particularly tetramethoxy-n-decane (TMOS) and tetraethyl ortho-decanoate. Ester (TEOS). The objective is to improve production costs and improve the quality of the final product. U.S. Patent Nos. 4,680,048, 4,681,615 and 5,207,814 or European Patent No. 5,8,086 It is disclosed in (3) 1309231 which also discloses the addition of vermiculite to the sol under the shape of pyrolysis or colloid. According to the contents of these patents, in the method of manufacturing an optical component device, particular attention is paid to the gelling step and, in particular, according to European Patent No. 5,86,013, which is condensed above the gel. The critical temperature of the solvent contained is quite good with the pressure final product, however, the high critical drying technique is built with a specific material and, in addition, it consumes. U.S. Patent No. 5,243,769 and U.S. Patent No. 5,473,826, the entire disclosure of which is incorporated by the sol-gel process, the force being lower than the critical enthalpy of the gel solvent, including immersion in the dry and dissolved in a pressure chamber and increasing its temperature. The gel underneath is solidified. It is in an inert gas saturated with the above solvent vapor, and the inert gas is not used and the internal pressure is not continuously monitored. The deviation from the pressure versus the critical enthalpy is lower, and all individual amounts of dry solvent are used in the pressure chamber, which forces the harvesting procedure. The applicant of the present invention has found that it is possible to achieve a method which does not have the above-mentioned disadvantages, which is also the main object of the present invention, the gel-gel technique for producing a gel, and the case where there is a high deviation from the critical pressure of the solvent. Drying under this method can also prepare and separate any of the target intermediates, sols, or gels prior to heat densification. Such intermediate products are instead an additional target of the present invention and they are also within the scope of this. : The oxide obtained is almost the final (polycondensation) gel drying, which is carried out. After the operation requires a lot of energy to reveal the temperature and the pressure inside the drying agent, in the former, the latter, the solvent temperature method includes the method of manufacturing the glass to be used later, including the temperature and condensation of the solvent. gum. Of course, for example, the manufacture of the hydrolysis is divided into the invention of the invention 130923⁄4 pieces (4) Method 2A: Patent Application No. 93100697 r._______ Chinese manual replacement page Republic of China August 29, 1994 Amendment I ΐ :i yl·.. Ή '-ϊ · ;-;·. . , v : i 94; 8/19 _____ ' Therefore an object of the invention is a method for producing a glass article comprising the following operations: a) preparing at least one of the following chemical formulas An aqueous solution or hydroalcoholic solution of a compound, or a suspension,
Xm - Μ - (OR)n.m 其中Μ爲屬於週期表第3, 4或5族元素之陽離 子’ η表陽離子價數，X爲！^或〇Rl，！^與r可 相同或不同’ m爲0或小於3的整數，R與1^爲 具有至多達12個碳原子數之烴基； b )水解上述化合物（溶液或懸浮液）而得所謂的溶 膠； c )選擇性添加可能的M2On之膠體懸浮液； d)膠凝該溶膠； e )用非質子型溶劑取代凝膠細孔溶劑； Ο於一壓力室內將凝膠凝固； g)將惰性氣體灌入壓力室內； h )將壓力室加熱一段設定時間以達到預定的溫度與 壓力値’該溫度與壓力値係低於凝膠溶劑之相關 臨界値，及進行蒸發； i) 放出蒸氣減低壓力室之壓力； j) 以惰性氣體沖洗壓力室； k) 冷卻經乾燥之凝膠並由壓力室取出； 1 )經由在預定溫度下加熱進行乾燥凝膠之合成以形 成無任何龜裂之玻璃物體。Xm - Μ - (OR)n.m where Μ is the cation value of the cation of the cation of the group 3, 4 or 5 of the periodic table, X is! ^ or 〇Rl,! And r may be the same or different 'm is an integer of 0 or less than 3, R and 1^ are hydrocarbon groups having up to 12 carbon atoms; b) hydrolyzing the above compound (solution or suspension) to obtain a so-called sol; c) selectively adding a possible colloidal suspension of M2On; d) gelling the sol; e) replacing the gel pore solvent with an aprotic solvent; coagulating the gel in a pressure chamber; g) filling the inert gas Entering the pressure chamber; h) heating the pressure chamber for a set period of time to reach a predetermined temperature and pressure 値 'the temperature and pressure 値 is lower than the critical threshold of the gel solvent, and evaporating; i) releasing the vapor pressure reducing chamber Pressure; j) flushing the pressure chamber with an inert gas; k) cooling the dried gel and taking it out of the pressure chamber; 1) synthesizing the dried gel by heating at a predetermined temperature to form a glass object free of any cracks.
(5) 1309231 步驟a )之膠體溶液（溶膠）係經由將根據上述化學 式的一或多種金屬氧化物先質與水或水/醇混合，加上酸 或鹼催化劑而製備的。如上述，Μ爲陽離子，n爲價數， 屬元素週期表第3，4或5族之元素，特別是Si，Ge，Ti 與A1，較佳者爲Si。對於X之所有可能意義，較佳者爲 烷氧基，特別者爲甲氧基，乙氧基，環氧基與丁氧基。 水解也於室溫下進行，且其可進行一段從5分鐘至超 過4小時之時間，直到形成構成膠體溶液成分的陽離子之 水合氧化物爲止。在膠凝之前，可於所得溶膠中添加至少 一所含陽離子的氧化物之膠體懸浮液。例如，如果使用包 括烷氧化矽或由烷氧化矽組成之先質時，上面所得膠體溶 液中可加入經由混合水，可能的溶劑，發煙矽石，酸或鹼 而製備的溶液/懸浮液。在膠凝起始之前的任何時，將水 解中斷或完成，即可產生一具有時間穩定性的溶膠，其可 經分離或儲存：此中間產物的取出也構成本發明之一項目 的。 根據步驟d)之溶膠膠凝可藉由將溶膠倒到一鑄模內 及使其靜置於低於9 0。C的溫度下一段從數分鐘至數小時 之時間。 膠凝結束時’淸洗凝膠，例如用有機溶劑，並將細孔 內部的溶劑用非質子型溶劑取代。此等非質子型溶劑較佳 者係選自丙酮’二氧雜環己烷，四氫呋喃，其中較佳者爲 丙酮。 將由是所得具有最可能少溶劑含量的凝膠形狀直接放 -9- (6) 1309231 在壓力室內，其中在封閉之後，通入惰性氣體，主要是氮 氣，其壓力適合於在壓力室溫度低於凝膠溶劑臨界溫度之 下’達到低於溶劑臨界壓力之總壓力，該總壓力係從接近 臨界壓力値之壓力値至高達約60%偏差及更高者。 於此’根據步驟h )，根據預定程式，增加壓力室溫 度以使凝膠溶劑蒸發。 藉由保持程式化溫度，將壓力室解壓（步驟i )以利 氣體與蒸氣之去除，例如藉由後續較佳地以氮氣進行的壓 力室淸洗予以輔助之操作。 淸洗結束後’冷卻壓力室，打開並移出乾凝膠（步驟 k ) 〇 呈從在步驟g)中所用鑄模得到的形狀之所得凝膠， 可根據本發明之附加目標，以此形式加以分離與應用，或 對其施以根據步驟1 )之玻璃化程序。 此種程序包括將乾凝膠置於爐中，將爐溫增高到 100°C以上’也可高達9 00〇C，且也在用來煅燒該凝膠的 含氧氣之氣圍下。於此處理之後，或其期間，可給入含氯 或氯先質之氣體混合物，以去除矽石中可能含有的氫氧化 物及/或將氣凝膠純化，爐溫係在1 〇 〇。C與1 2 5 0。C之間。 最後將爐溫增加到可使氣凝膠密實化以達到玻璃化之 値，此溫度’針對矽石材料而言，係在900。(：與165CTC 之間’係在一惰性氣圍之下，該氣體爲氦，氧，氯，及類 似物。任何爐處理之持續時間範圍爲從數十分鐘至許多小 時0 -10- (7) 1309231 頃由本案申請人對於在次臨界條件下操作的彼等程序 發現該方法之優點在於操作溫度與壓力仍然低於其他專利 之申請專利範圍所界定者（美國專利第5,243,7 6 9號與第 5,47 3,8 3 6 號）。 顯然地，另有其他優點爲可於壓力室內置入其量爲會 強迫隨後使用回收程序的乾燥溶劑之下操作。 所有上述與其他操作細節都可藉由閱讀下面的實施例 而變得更淸楚’該等實施例之目的爲示範說明本發明而非 對其目的加以任何限制。 【實施方式】 實施例1 在攪拌下，添加26‘1升之0‘01 N HC1，於9.4升 TEOS中。在連續攪拌60分鐘後，得到一透明溶液。在強 烈攪拌下添加5公斤粉末發煙矽石。特別適合於依此添加 者爲市售產品 Aerosil OX-50。藉由一非常強力的機械攪 拌約60分鐘使混合物均勻，然後用超音波勻化約〗〇分鐘 。對處理過的混合物施以離心後，置於一適當的玻璃容器 之內。將0_01 N氨水溶液添加於此分散液內，其量爲可 保證有可將該分散液倒在膠化容器內之時間。將處理過之 分散液倒在分別具有24毫米和80毫米的內徑與500毫米 和1100毫米的高度之許多圓筒容器內，於其中發生膠凝 〇 將該等圓筒封閉且與直徑爲6毫米之聚丙烯管互連。 -11 - (8) 1309231 24小時且膠凝完成之後，將一流體以5毫升/分的流速， 流經圓筒與互連管，該流體包括一水/丙酮混合物，開始 時的組成爲〗〇 〇 %水’直到4 8小時後爲無水丙酮。保持 無水丙酮入口流直到出口流體之水含量持續地低於0 . 1 % ，即使停止該流動超過4 8小時也一樣，然後再起始。 裝有按照上述處理過且稱爲濕凝膠之凝膠的兩個24 毫米內徑之圓筒，與一裝有4升丙酮的容器一起放到內部 容量爲413升之壓熱鍋內。於將壓熱鍋封閉且加熱到高達 8〇°C之後，給入氮氣直到內部總壓力爲48巴爲止。然後 以5 °C/時之速率增溫到高達225。(：，以在控制方式下使壓 熱器內部氣體逸出，以避免總壓力高出50巴。丙酮分壓 且壓熱器流體溫度都連續地低於臨界値使製程可在非臨界 情況下進行。於22 5。(：下，於24小時期間，將壓熱器解 壓到1巴，且於打開並取出兩樣品之前以氮氣淸洗，此時 的樣品爲呈圓柱狀的乾，非常多孔型之凝膠，爲稱氣凝膠 。將該等氣凝膠置於一爐內，關閉該爐且將溫度於24小 時內升高至800。(：，同時以5升/分之速率流入室溫空氣 。在此溫度且有氦氣流動下1 2小時以上之後，以1 〇 ° C/ 分鐘之速率將溫度提高至1 3 90。(：。將溫度保持在 1 3 90 °C 10分鐘，且然後仍在氮氣圍之下，於該爐爲封閉 之時，以10。C/分鐘之速率降低至800。(：，並且冷卻至室 溫。 所得樣本爲兩個無龜裂且具有圓柱形狀之玻璃體。 -12 - (9) 1309231 實施例2 將依據前述實施例1製成之兩濕凝膠與一有3 5升丙 酮之容器一起置入413升內容積之壓熱器內。於關閉壓熱 器且加熱至8 0 ° C之後’給入氮氣使壓熱器之內部壓力達 9巴。然後’以5°C /時之速率增溫至225 °C，以使壓熱器 內部氣體以控制方式逸出而避免總壓力高於3 2巴。(5) 1309231 The colloidal solution (sol) of step a) is prepared by mixing one or more metal oxide precursors according to the above formula with water or water/alcohol, plus an acid or base catalyst. As described above, ruthenium is a cation, and n is a valence, and is an element of Group 3, 4 or 5 of the periodic table, particularly Si, Ge, Ti and A1, preferably Si. For all possible meanings of X, alkoxy groups are preferred, particularly methoxy, ethoxy, epoxy and butoxy. The hydrolysis is also carried out at room temperature, and it can be carried out for a period of from 5 minutes to over 4 hours until a hydrated oxide of a cation constituting a colloidal solution component is formed. A colloidal suspension of at least one cation-containing oxide may be added to the resulting sol prior to gelation. For example, if a precursor comprising or consisting of an alkoxylated cerium oxide is used, a solution/suspension prepared by mixing water, a possible solvent, a fumed vermiculite, an acid or a base may be added to the colloidal solution obtained above. At any time prior to the onset of gelation, the hydrolysis is interrupted or completed, producing a time-stabilized sol which can be isolated or stored: the removal of this intermediate product also constitutes one of the items of the present invention. The sol gelation according to step d) can be carried out by pouring the sol into a mold and allowing it to stand below 90. The temperature of C ranges from a few minutes to several hours. At the end of the gelation, the gel is washed, for example, with an organic solvent, and the solvent inside the pores is replaced with an aprotic solvent. Preferably, such aprotic solvents are selected from the group consisting of acetone 'dioxane, tetrahydrofuran, with acetone being preferred. The shape of the gel obtained from the most likely solvent content is directly placed in the pressure chamber, wherein after the closure, an inert gas, mainly nitrogen, is introduced, the pressure of which is suitable for the temperature in the pressure chamber is lower than Below the critical temperature of the gel solvent 'to reach a total pressure below the critical pressure of the solvent, the total pressure is from a pressure close to the critical pressure 値 to a deviation of up to about 60% and higher. Here, according to the step h), the pressure room temperature is increased in accordance with a predetermined program to evaporate the gel solvent. By maintaining the programmed temperature, the pressure chamber is depressurized (step i) to facilitate the removal of gases and vapors, for example by subsequent pressure chamber scrubbing, preferably with nitrogen. After the end of the rinsing, 'cooling the pressure chamber, opening and removing the xerogel (step k) 〇 the resulting gel from the shape obtained in the mold used in step g) can be separated in this form according to the additional object of the present invention. With the application, or according to the vitrification procedure according to step 1). Such a procedure involves placing the xerogel in a furnace to increase the furnace temperature above 100 °C, or up to 900 ° C, and also under the oxygen-containing gas used to calcine the gel. After this treatment, or during this period, a gas mixture containing chlorine or chlorine precursor may be fed to remove hydroxides which may be contained in the vermiculite and/or to purify the aerogel at a temperature of 1 Torr. C and 1 2 5 0. Between C. Finally, the furnace temperature is increased to allow the aerogel to be densified to achieve vitrification, which is at 900 for vermiculite materials. (Between 165CTC and '165CTC', the gas is helium, oxygen, chlorine, and the like. The duration of any furnace treatment ranges from tens of minutes to many hours 0 -10- (7 1309231 It is found by the applicants of the present invention that they operate under subcritical conditions. The advantage of this method is that the operating temperature and pressure are still lower than those defined in the patent application scope of other patents (US Patent No. 5,243,7 6 9) And No. 5, 47 3, 8 3 6). Obviously, there are other advantages that can be built into the pressure chamber to operate under a dry solvent that would force subsequent recycling procedures. All of the above and other operational details are It is to be understood by reading the following examples which are intended to illustrate the invention and not to limit its purpose. [Embodiment] Example 1 Adding 26'1 under agitation Raise 0'01 N HC1 in 9.4 liters of TEOS. After continuous stirring for 60 minutes, a clear solution is obtained. 5 kg of powdered smoky vermiculite is added under vigorous stirring. It is especially suitable for commercially available products. Aerosil O X-50. The mixture was homogenized by a very strong mechanical agitation for about 60 minutes and then homogenized by ultrasonic waves for about 〇 minutes. The treated mixture was centrifuged and placed in a suitable glass container. A 0_01 N aqueous ammonia solution is added to the dispersion in an amount to ensure that the dispersion can be poured into the gelation vessel. The treated dispersion is poured into an inner diameter of 24 mm and 80 mm, respectively. In many cylindrical containers with heights of 500 mm and 1100 mm, gelation occurs therein, the cylinders are closed and interconnected with polypropylene tubes having a diameter of 6 mm. -11 - (8) 1309231 24 hours After the gelation is completed, a fluid is passed through the cylinder and the interconnecting tube at a flow rate of 5 ml/min. The fluid comprises a water/acetone mixture, initially consisting of 〇〇% water' until after 48 hours. It is anhydrous acetone. Keep the anhydrous acetone inlet stream until the water content of the outlet fluid is continuously lower than 0.1%, even if the flow is stopped for more than 48 hours, and then start again. It is treated as described above and is called wet coagulation. Gum gel of two 24 The inner diameter cylinder is placed in a pressure cooker with an internal capacity of 413 liters together with a container containing 4 liters of acetone. After the autoclave is closed and heated up to 8 ° C, nitrogen is supplied until The internal total pressure is 48 bar. Then it is heated up to 225 at a rate of 5 °C / hour. (:, in the control mode, the internal gas of the autoclave escapes to avoid the total pressure is 50 bar higher. The partial pressure and the autoclave fluid temperature are continuously below the critical threshold so that the process can be carried out under non-critical conditions. At 22: (under:, during 24 hours, the autoclave is decompressed to 1 bar and opened The two samples were taken out and flushed with nitrogen. The sample at this time was a cylindrical dry, very porous gel called an aerogel. The aerogels were placed in a furnace, the furnace was turned off and the temperature was raised to 800 within 24 hours. (:, at the same time, flow into the room temperature at a rate of 5 liters / minute. After this temperature and the helium flow for more than 12 hours, increase the temperature to 1 3 90 at a rate of 1 〇 ° C / minute. The temperature was maintained at 1 3 90 °C for 10 minutes and then still under nitrogen blanket, and at the rate of 10 ° C/min, it was reduced to 800 when the furnace was closed. (:, and cooled to room temperature The resulting sample was two glass bodies without cracks and having a cylindrical shape. -12 - (9) 1309231 Example 2 Two wet gels prepared according to the foregoing Example 1 were placed together with a container of 35 liters of acetone. Into the 413 liter internal volume of the autoclave. After the autoclave was turned off and heated to 80 ° C, 'nitrogen was supplied to bring the internal pressure of the autoclave to 9 bar. Then 'increasing at 5 ° C / hour Warm to 225 °C to allow the internal gas of the autoclave to escape in a controlled manner to avoid a total pressure above 32 bar.
該壓熱器之流體壓力與溫度係持續低於丙酮，亦即凝 膠細孔內之流體，之臨界値，使得該程序係在非臨界狀況 下進行。於22 5 °C下，24小時期間，將壓熱器解壓到1 巴，且於打開取出兩樣品之前，以氮氣淸洗，此等樣品爲 呈圓柱狀的乾，非常多孔型之凝膠，稱氣凝膠。將該等氣 凝膠置於一爐內，關閉該爐且於24小時內，於以5升/分 鐘的速率流入衝撞空氣（bumb air?室內room air?)之下’ 將溫度升高至80(TC。在此溫度且有氦氣流動下12小時 以上之後，以1 0。C /分鐘之速率將溫度提高至1 3 9 〇 ° c。保 持溫度於1 3 9 0。C 1 0分鐘，且然後仍在氮氣圍之下’於該 爐爲封閉之時，以分鐘之速率降低至800°C’並且 冷卻至室溫。 所得樣品爲兩個無龜裂的圓柱狀玻璃體。 實施例3 將依據前述實施例1製成之兩濕凝膠與一有4升丙酮 之容器一起置入413升內容積之壓熱器內。於關閉壓熱器 且加熱至80。(：之後，給入氮氣使壓熱器之內部壓力達47 -13- (10) 1309231 巴。然後，以50°C/時之速率增溫至25 0°C，以使壓熱器 內部氣體以控制方式逸出而避免總壓力高於5 0巴。 該壓熱器之丙酮壓力係持續低於臨界値，使得該製程 可在非臨界狀況下進行。於22 5 °C下，24小時期間，將 壓熱器解壓到1巴壓力，且於打開及取出兩樣品之前，以 氮氣淸洗，此等樣品爲呈圓柱狀的乾，非常多孔型之凝膠 ，稱氣凝膠。將該等氣凝膠置於一爐內，關閉該爐且於 24小時內，於以5升/分鐘的速率流入室溫空氣之下，將 溫度升高至800°C。在此溫度且有氦氣流動下12小時以 上之後，以l〇°C/分鐘之速率將溫度提高至1 3 90°C，仍在 氦氣流之下。保持溫度於I 3 90°C10分鐘，且然後仍在氮 氣圍之下，於該爐爲封閉之時，以1 〇°C/分鐘之速率降低 至8 00°C，並且冷卻至室溫。 所得樣品爲兩個無龜裂的圓柱狀玻璃體。 -14-The fluid pressure and temperature of the autoclave continue to be lower than that of the acetone, i.e., the fluid within the pores of the gel, which makes the process non-critical. The autoclave was depressurized to 1 bar at 22 ° C for 24 hours, and was flushed with nitrogen before opening and taking out the two samples. These samples were cylindrical dry, very porous gels. Called aerogel. The aerogels were placed in a furnace, and the furnace was turned off and flowed into the collision air (bumb air? indoor room air?) at a rate of 5 liters/min within 24 hours to raise the temperature to 80. (TC. After this temperature and with helium flow for more than 12 hours, increase the temperature to 1 3 9 〇 ° c at a rate of 10 ° C / min. Keep the temperature at 1 3 9 0. C 10 minutes, And then still under nitrogen atmosphere 'when the furnace is closed, reduce to 800 ° C at minute rate and cool to room temperature. The resulting sample is two crack-free cylindrical glass bodies. Example 3 The two wet gels prepared according to the foregoing Example 1 were placed in a 413 liter internal volume autoclave together with a vessel having 4 liters of acetone. The autoclave was turned off and heated to 80. (: After that, nitrogen was fed. The internal pressure of the autoclave is 47 - 13 - (10) 1309231 bar. Then, the temperature is increased to 25 ° C at a rate of 50 ° C / hour to allow the internal gas of the autoclave to escape in a controlled manner. The total pressure is above 50 bar. The acetone pressure of the autoclave is continuously below the critical enthalpy, so that the process can be carried out under non-critical conditions. 22 At 5 °C, during 24 hours, the autoclave was decompressed to a pressure of 1 bar, and washed with nitrogen before opening and taking out the two samples. These samples were cylindrical dry, very porous gel. , called aerogel. The aerogels were placed in a furnace, the furnace was turned off and the temperature was raised to 800 ° C at room rate of 5 liters per minute for 24 hours. After this temperature and under helium flow for more than 12 hours, the temperature is increased to 1 3 90 ° C at a rate of 10 ° C / min, still under the helium flow. Keep the temperature at I 3 90 ° C for 10 minutes And then still under nitrogen, when the furnace is closed, reduce to 800 ° C at a rate of 1 ° C / min, and cool to room temperature. The resulting sample is two crack-free cylinders Vitreous body. -14-